1. Field of the Invention
The present invention relates to a contents player, program, and method which plays multimedia data.
2. Related Art
In a conventional contents player for television broadcasting and a DVD, contents are provided to a user such that multimedia data such as a moving image or audio data is merely broadcasted or played. In recent years, in order to provide more interactive contents to a user, a configuration which causes a contents player to execute not only an ordinary playing function but also various functions cooperating with playing of multimedia data such as a function of designating a display position or a playing timing of multimedia data including a still image, character information, or the like, a function of detecting a remote control input from a user to reflect the remote control input on a screen, and a function of communicating with a server device on the Internet or a home network is realized. For example, the configuration has been realized to digital broadcasting which starts in recent years or game contents.
In particular, as a method of describing contents cooperating with multimedia data such as a video image, audio data, and a still image, as shown in BML (Broadcast Markup Language) and HTML (Hypertext Markup Language) and SMIL (Synchronized Multimedia Integrate Language), entire contents are described in a XML—(extensible Markup Language) based language, and processing description by script languages JavaScript or ECMAScript is written in an XML document, and an interactive function is called as API from a script.
In such contents having interactivity, a function of storing contents related information set or acquired by an operation by a user in a storing medium through a contents player and a function of reading out the contents related information from the storing medium are also used. The functions are used as described below. That is, for example, with regard to video contents such as a DVD, a display language setting set by a user is stored in a built-in memory, and save data such as a high score of a game is stored with regard to game contents.
Japanese Patent Laid-Open No. 2001-337864 proposes a method in which an application program operated on an operating system of another computer prepares data called a policy file when data is read or written from/in a data storing device connected to the computer, records access control information in the policy file, and refers to the access control information to realize access controls for respective applications.
Japanese Patent Laid-Open No. 2004-5084 proposes a method in which an access management mechanism transparently provides access control information for data written in the data storing device by the application program and refers to the access control information to realize access controls of respective applications.
In a conventional storing mechanism of data from contents is mainly used a method that small amount of setting information is written in a limited storing destination such as a memory built in a contents player or a storing device inserted into a specific slot of the contents player. For example, in digital broadcasting, it is determined that, as a data storing destination, one built-in memory (NVRAM: a nonvolatile memory in which contents are not erased in an OFF state) is necessarily included in a digital television serving as a contents player. In digital broadcasting, a document for contents control is described in contents by a specification descriptive language BML (Broadcast Markup Language) and a script Language ECMAScript. As API available from the ECMAScript, API for simple reading and writing of data is defined for a built-in memory.
However, with diversification of contents in future digital broadcasting, contents having higher interactivity are expected to be developed for an advanced DVD player in the future, an advanced recorder in the future, a mobile AV terminal which can hold AV contents in SD card, or the like. In the contents having the higher interactivity, it can be considered that a function of reading or writing variable data from/in an arbitrary storing device such as an SD card or an NAS (Network Attached Storage) is desired. For example, the following using method is supposed.
An arbitrary screen shot in video contents is stored in an SD card connected to a contents player. A user moves the SD card to a printer to perform printing.
A large amount of privileged video data related to certain contents is downloaded from a server and stored in the NAS in the home network. When the user plays the contents, the contents access the NAS to play the privileged video data to make the user possible to view the privileged video image.
Here, when reading and writing of data X stored by certain regular contents are not restricted in any way, for example, when a user plays malicious contents without noting the contents being malicious contents, the data X may be disadvantageously stolen from the malicious contents or altered or deleted. On the other hand, when the presence of data X stored by certain regular contents is detected by other regular contents of the same provider, a service which causes new extra contents to appear as a privilege for a user who purchases a large number of contents can be supposed.
Therefore, any access limitation mechanism which can set accessibility/inaccessibility per contents or providers to the data X which has stored by certain contents is desired.
However, in the conventional technique, there is no method of making it possible to read and write data from digital broadcasting or contents such as DVD contents to an arbitrary storing device such as an SD card or a NAS in consideration of access limitation per contents or providers.
On the other hand, as one service cooperating with contents, the appearance of a service which performs not only reading and writing of data from the contents but also control of an in-house device such as a household electrical appliance, audio-video equipment, or a toy may be considered. For example, the service includes transmission of an instruction of reservation of recording from an EPG (Electronic Program Guide) to an HDD recorder. Also this case is in danger of unintentionally operating the in-house device by playing malicious contents. However, there is not method of making it possible to control the in-house device in consideration of access limitation.